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P. EVANS.

DIFFERENTIAL DRY PIPE VALVE.

APPLICATION FIIED Nov. 7. 1919.

v1,4:18 1&0. Patented May 30, 1922.

2 SHEETS-SHEET I.

P.` EVANS. y DIFFERENTIAL DRY P|PE vALvE.

APPLICATION FILED NOV. 7, 15H9.`

Patented May 30, 1922.

2 SHEETS-SHEET 2.

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UNITED sraras POWELL EVANS, OF PHILADELPHIA., PENNSYLVANIA, ASSIGNGR TO GLOBE AUTO MATIC SPRINKLER COMPANY, O?? PHLADELIJHIA, PENNSYLVANIA, A CORPORA- |lION OF PENNSYLVANIA.

DIFFERENTAL DRY-3PPE VALVE.

Specification of Letters Patent.

Patented May 30, 1922.

Application filed November 7, 1919. Serial No. 336,462.

To all whom t may concern.:

Be it known that l, POWELL EVANS, a citizen of the Unite-d States, residing in Philadelphia, Pennsylvania, have invented Differential Dry-Pipe Valves, of which the following is a specification.

@ne object of this invention is to provide means for insuring, assisting and accelerating the operation of the dry pipefvalve of an automatic fire extinguishing system upon theopening` oit' one or moreof the sprinkler heads of such system g-the invention more particularly contemplating a' novel device for causing air under pressure to act on the under side of the air ,clapper in suchmanner as to lessen the time requiredvior the operation ofthe dry pipe valve and thushasten the delivery of water to the open sprinkler head.

Another object of the invention is to provide an automatic device for delivering air under pressure to the atmospheric chamber ot' a dry pipe valve for'the purpose of accelerating the opening of the air valve when the pressure of the air in the system to which the device is connected shall have fallen to a. predetermined point.

It is also desired to provide a dry pipe valve of thedifferential type whose parts shall be of such arrangement and design as to permit of a material reduction in the dimensions of the device ttor a given capacity ,-the invention more especially contemplating a novel construction and arrangement of the air and water clappers whereby it is possible to mount these in cooperative positions' within a relatively small and compact casingstructure. s

I further desire to provide a dry pipe valve with a novel form of air clapper particularly designed to lit over and enclose a water clapper, Athe whole being assembled with a view to making it possible tor air at a deinite pressure acting on theair clapper to normally maintain the water clapper closed against the higher pressure acting thereon.

These objects and other advantageous ends I attain as hereinafter set forth, reference being had to the accompanying drawings, in which,

v extension Fig. 1 is a vertical section of a dry pipe valve equipped with my invention;

Fig. 2 is a vertical section illustrating an arrangement and construction of water and. air clappers ydifferent from'that of Fig. 1;

Fig. 3` is a horizontal section on the line 8 6, Fig. 2, and

Fig. 4 is a perspective view of the drip valve shown in Figs. 2 and 3.

In Fig. 1 of the above drawings, 1 represents themain casing' of a dry pipe valve having la bottom opening or inlet 2 designed for connection to a water supply system and having a top opening` or outlet 3 designed for connection to a sprinkler system. This casing is divided into two chambers by an inclined partition in which is formed a circular opening` whose central point lies in the center line` with the two openings 2 and 3.

The opening 2 has a seat 4L for the recepl tion of a water valve or clapper 5, which is connected to an arm 6` rotatably mounted on a pivot pin or bar 7 so aste be free to swing` `with the valve 5 into the position shown in 6 in such manneras to hold the clapper 5 closed as long as said air valve is closed. The latter also has mounted on its lower tace a flexible seat-engaging ring 13 'for insuring a tight joint with the seat 9 and so formed and attached that it has a substantially frusto-conical form when not engaging said seat.

Said air valve or clapper 1() is formed with a segmental, rearwardly projecting,r 14- substantially concentric with its pivot pin 11 and formed with a series of ratchet teeth 15 designed to coact with av =pawl 16 pivotally hung from a pin 17 supported by a pair ot lugs 1S. The latter are preferably formed as part ot and project' inwardly from a cover plate 19 designed to normally close the air chamber 2O of the dry pipe valve and said pawl is so carried that its lower or toothed end tends at all times to' swing toward the segment let or" the air clapper so as to engage the teeth thereof and retain the clapper in any position to which it may rise from its seat.

The upper end 21 oi the pawl is extended into position to ooact with a stop 22 placed on the cover plate 19 to limit the swing ot the main or lower portion ot the pawl and thereby insure its occupying a position to coact with the segment when the cover plate is applied.

In accordance with one feature of my invention, I mount on or adjacent the dry pipe valve a two-part casing 28 and 24 and clamp between its parts a flexible diaphragm 25. This casing is so mounted that the part 23 is above the part 24 and the latter has two pipes 2G and 27 ot which the first is connected to the air chamber 2O of the dry pipe valve, while the second is connected to the atmospheric chamber 28 thereof which has a small valve seat 29 leading to a drain and constituting a normally open trap controlled by a valve 30 hung 'from one arm ot' a lever 3l tulcrumed on the pivot pin 7 and having its other arm engaged by the arm 6 of the water clapper.

The arrangement is such that the trap valve 30 is held open as long as the water clapper 5 is closed, although by reason of its weight, it will automatically close as soon as said clapper opens and allows the arm 6 to swing upwardly on its pivot pin 7.

The diaphragm 25 has formed through it a small opening 36, which it desired, may be closed by a check valve 37 so placed as to permit 'How 'from the chamber 2t into the chamber 23 while preventing a return flow. While the opening oit the pipe 2G to the chamber 24j ot the accelerator casing is unrestricted, this latter is so formed adjacent the opening to the pipe 27 as to provide a passage 35 having` a valve seat Litl. and a cooperating valve 39 supported by a stirrnp 38 carried by or connected to the diaphragm 25. This valve 39 is at all times urged toward its seat 4l by a spring 40 and normally holds the diaphragm 25 in its uppermost position.

With the above described arrangement of parts, under conditions ot operation the water under pressure in the supply system acts through the opening 2 against the water clapper 5, which however is normally maintained closed by reason ot the air pressure in the sprinkler system acting in the chamber 20' against the air clapper l0. The trap valve 3() is thus maintained in its open position so that atmospheric pressure exists in thev sprinkler system iills the chamber 24e ot the accelerator casing and passing through the opening 36 in the diaphragm 25 also tills the chamber 23 thereof. Since however the pipe 27 and passage 35 contain air at atmospheric pressure, the spring et() insures that the valve 39 is closed.

It now an automatic sprinkler opens at some point of the system connected to the pipe 50, there is a resulting reduction ot the air pressure in the chamber 2O of the dry pipe valve, and when this pressure reaches a predetermined low point, the water pressure in the inlet 2 causes unseating of the air clapper l() and the release and opening oiu the water clapper 5. By means ot the accelerator device above described however, before the pressure in the chamber 2O has fallen sutiiciently tar to permit unseating ot the air clapper, it is suiiiciently reduced in the chamber 24 to allow the air in the chamber 23 to torce downwardly the diaphragm 25, the valve 3T heilig closed or the opening through the diaphragm being relatively restricted. The accelerator valve is thereupon opened so that the air under reduced pressure -trom the chamber 2O and trom the sprinkler system is delivered through the passage 35 and pipe 2T to the atmospheric chamber 28 ci: the dry pipe valve.

Even it the water clapper 5 has not opened sufficiently Jr'ar to allow closing ot the trap valve 30, this air under pressure acting on the relatively large area ot the under tace of the air clapper l0, exerts a torce tending to unseat said clapper and thus materially assists the water clapper, causing opening both ot the air clapper and ot said water clapper in a shorter time after the opening` of an automatic sprinkler head in the system, than would be the case itthe opening ot the air clapper was unassisted. The delivery of water to the open sprinkler head is thus insured in a shorter time atteithe beginning ot the tire which caused such head to open, and there is a considerably iiu'freascd probability of e\tinguishing the fire before it has attained great hemlway than would ordinarily be the case in the absence ot my invention.

It desired the dry pipe valve may be constructed as shown in Figs. 2 and 3, with a cylindrical extension l constituting a seat 'for a water clapper 5a mounted on an arm 61. pivoted on or rotatable with a hinge or pivot pin 7a extending across the casing'. The seat sleeve la is threaded into the sides ot the inlet passage or opening- 2 and is outwardly flanged to clamp in place a metal ring 53 carrying an outwardly projecting, iieXible, substantially truste-conical seat element 9a, designed to cooperate with the annular tace oit the air clapper 10, This latter is mounted upon a second pivot pin or shaft lla extending` across the casing l parallel with the pin or shaft 7a of the water valve and on the opposite side of the seat sleeve Lla therefrom.

It is noted that thel flexible seat ring 99L for the air clapper lOL projects at a level below the top of the seat sleeve 4L and is eccentric thereto, its center line being displaced toward the pivot of the water clapper YL in order that the air clapper l0, which is upwardly dished or concave so as to receive within it said water clapper, may clear the latter under operating conditions. Within the hollow of the air clapper is mounted a bearing plate 12a designed to engage the arm 6a of the water clapper so as to hold the latter closed as long as a ring 13a on the face of the air clapper remains in engagement with its seat 9a.

In order to insure that the air clapper shall remain open after it has been raised a predetermined distance from its seat, l provide it with a toothed segment 14a as before and pivotally mount a Weighted pawl or tooth 16EL on a pin 17a carried by a plug 52. This is threaded into a suitably formed opening in the casing la in such positionthat the pawl at all times tendsto swing toward and remain in engagement with the toothed edge of the segment 14a ;-the arrangement being such that the water clapper, after moving out of engagement with its flexible seat 9a, is retained in its raised or open position. As before the chamber between the two valves 10a and 52L is normally open to the atmosphere through a drain passage 54 terminating in a valve seat 29, and a valve 30a is so hung on a level 30b carried by the pivot spindle 721 as to be held open as long as the water valve is closed and permitted to close when said latter valve is open.`

lVith the above described arrangement of parts, the pipe 27 leading from the accelerator (which being' of the construction shown in Fig. l, is omitted'from Figs. 2 and 3) communicates with the atmospheric chamber between the air and water clappers through an opening suitablyfplaced in the ring 53 and the pipe 26 as before, enters the air chamber 20m. Under normal conditions the pressure of the air in the sprinkler system, acting in the chamber 20a of the valve casing, holds the air clapper 10' to its yielding seat 9a, and through the plate 12a, holds the water clapper 5a upon its seat sleeve 4a against the relatively higher water pressure exerted through the inlet 2. Vhen however there is a reduction of the air pressure in the chamber 20a such as would be caused by the opening of al sprinkler head in the sysvtem connected thereto, the air clapper l0 is .forced from its seat, partly by the pressure of the water acting through the clapper 5a and arm 6a and partly by the air under pressure delivered to the space 18a between the clappers by the accelerator through the pipe 27, so that said air clapper swings up and to o'ne side of the line of the .inlet 2 and outlet into a position in which it is retained by the pawl 1G engaging a tooth of the segment lili". This upward movement of the air clapper permits the water clapper to swing in the opposite direction ou its pivot pin 7, thus leaving a clear passage for the water to vflow from the inlet through the chamber 20"L and into the sprinkler system through the outlet 3.

According to one featureof my invention therefore, there is a supply of air under pressure deliveredto the atmospheric chamber of the dry pipe valve after the opening' of a sprinkler head, with the result that the time elapsing before water flows into and is delivered from the sprinkler system is materially reduced, and it is note-d that the cross sectional areas of the conduits connecting the chamber 20 with the acceleratorl After the operation of the system, theL closure of the water clapper 5 and of the air clapper l0 permits of air under pressure being again delivered from the chamber 20 to the sprinkler system, and the consequent flow of air to the chamber 24 of the accelerator casing, acts on the diaphragm 25 to again allow seating of the valve 39, so that the various parts are in positions for operation.

I claim.:

l. An accelerator consisting of a casing having an inlet and an outlet and provided with a closed chamber connected to receive fluid under pressure from the inlet; a normally closed valve between said inlet and outlet; with a member movable under the action of the fluid under pressure in said chamber for openingthe valve when the pressure .in the inlet falls to a predetermined point.

2. An accelerator consisting of a casing having a movable element dividing it into chambers of which one is provided with an inlet and an outlet; a valve mounted between the inlet and outlet for controlling` the latter and operatively connected to said member; and means normally holding said valve closed, the second chamber being normally filled with fluid under pressure for moving the member and opening the Valve when a predetermined fall of pressure ocmismo nected between the inlet and outlet for controlling the latter; with means connecting the valve to the diaphragm and positioned to cause opening oi" said valve when a predetermined unbalanced pressure is exerted on the diaphragm.

4t. An accelerator consisting' ot a casing; a diaphragm dividing said casing into chambers and having a restricted passage, one oi? said chambers having an inlet and an outlet; a valve interposed between said inlet and outlet for controlling the latter; and means for mechanically connecting said valve with the diaphragm.

5. An accelerator consisting ot a casing; a diaphragm dividing said casing into chambers connected through a restricted passage, one of said chambers having an inlet and an outlet; a valve interposed between said inlet and outlet for controlling the latter; means for operatively connecting said valve with the diaphragm; and a spring normally holding said valve closed.

G. The combination in a differential dry pipe valve of a casing` having a water inlet and an outlet; a water valve tor closing the inlet; with a concave structurally independent air valve fitting over and Ienclosing` the water valve when this is in its closed position; said latter valve being mounted to open in a direction opposite that taken by the water valve.

7. The combination in a differential dry pipe valve of a casing having a water inlet and an outlet; a valve seat for said inlet; a second valve seat extending eccentrically around Athe lirst valve seat and in a plane parallel thereto; a water valve mounted to coact with the first valve seat; with a concave structurally independent air valve positioned to engage the second seat and enclose the water valve.

8. Thecombination in a differential dry pipe valve of la casing having a water inlet and an outlet; two valves pivotally mounted on opposite sides of the inlet and formed to lit one inside of the other; with eccent-rically disposed seats for said two valves.

9. rllhe combination in a diiterential dry pipe valve of a casing having a water inlet and yan out-let; a seat sleeve for the inlet; a valve ring clamped in place by said seat ring; with two valves pivoted on opposite sidesot the inlet and formed to fit one inside of the other in positions to respectively coact with the seat sleeve and with the valve ring.

In witness whereof I affix my signature.

POVELL EVANS. 

